1. Field of the Invention
The present invention relates to a treating apparatus and method for treating a surface of an object such as etching, ashing, cleaning, surface-reforming or the like. In particular, the present invention pertains to a technical field of a treating apparatus and method for carrying out surface treatment of a surface of an object by employing a negative hydrogen ion. Further, the present invention pertains to a technical field of a method for manufacturing a semiconductor device for surface-treating the inside of a groove such as a contact hole or the like, or a surface to be treated consisting of electric conductors in a wiring (electrode) forming step in a manufacturing process of the semiconductor device, and then, depositing the conductor on the inside of the groove or on the surface of the conductor.
2. Related Background Art
In a surface treatment such as conventional plasma etching, a positive ion has been utilized.
In FIG. 30, there is shown a cross section of a conventional parallel flat-plate type plasma treating apparatus. In FIG. 30, reference numeral 201 denotes a high-frequency power source; reference numeral 202 denotes support means compatible with an electrode to which a high-frequency power is applied; W denotes a semiconductor substrate as an object; IS denotes an ion sheath; PM denotes plasma; reference numeral 206 denotes a vacuum container; reference numeral 205 denotes a grounded opposite electrode; reference numeral 203 denotes a process gas introducing inlet; and reference numeral 204 denotes an air exhaust port. In this apparatus, when a high frequency is applied to the support means 202, plasma PM is generated between the support means and an opposite electrode installed in parallel to a substrate. At this time, between the plasma and the support means 202 and between the plasma and the vacuum container 206, an electron depletion area called an ion sheath xe2x80x9cISxe2x80x9d is generated due to a difference in easiness of movement of the ion and electron in the plasma, and the plasma becomes a positive potential to the electrode on average. In the support means 202, to which a high frequency is applied, a potential difference against the plasma is greater than the grounded opposite electrode 205, and some hundreds of volts are produced at maximum. A positive ion in the plasma is accelerated by a potential of such a sheath, and the accelerated ion is incident with a certain energy. A substrate surface is etched and cleaned utilizing this positive ion. In a process for manufacturing the semiconductor device, only the positive ion is utilized as described above, and a negative ion is not utilized. However, recently, attention has focused on the negative ion in plasma processing, and there have been proposed some plasma treatment methods utilizing a negative ion.
For example, in Japanese Patent Application Laid-Open No. 8-181125, there is disclosed a plasma etching treatment in which a substrate surface is alternately irradiated with positive and negative oxygen ions utilizing an after-grow plasma of oxygen in order to ensure electrification with a substrate.
In addition, in Japanese Patent Application Laid-Open No. 9-82689, there is disclosed a plasma treating apparatus for treating a substrate by neutral active particles without employing electrified particles such as ions. Similarly, in T. Mizutani and S. Nishimatsu; xe2x80x9cSputtering Yield and Radiation Damage by Neutral Beam Bombardmentxe2x80x9d, J. Vac. Sci. and Technol., Vol. A6, p1417, (1988), there is disclosed plasma treatment using neutral particles.
Further, in Japanese Patent Application Laid-Open No. 7-122539, there is disclosed a surface treatment method for supplying negative fluorine ion beams of 20 eV or less to a hydrogen dissociated and adsorbed silicon oxide, and etching the silicon oxide.
Plasma cleaning treatment as well as plasma etching are applied to a semiconductor device manufacturing process. In the semiconductor device, when a connection between an impurities diffusion layer formed on a surface side of a substrate and a metal wiring layer is made via a contact hole provided at an insulation layer, an aspect ratio of the contact hole (depth/aperture dimensions) greatly exceeds 1. Therefore; as a method for forming a wiring metal film in the contact hole, there is used a sputter method, and as a method for embedding the contact hole even if the aspect ratio is 2 or more, there is used a chemical air phase growth method (CVD method). Tungsten, aluminum, copper, gold or the like are considered for embedding metal into a fine contact hole using the CVD) method. With respect to aluminum, a high-quality film and a high filling speed are achieved with a heat CVD method using DMAH (dimethyl aluminum hydride) and hydrogen, and attention is focused on it as a material for embedding the contact hole, which is the second best to tungsten.
An aluminum wire forming process with the CVD method is carried out as follows: First, after a contact hole has been formed on an insulation film by dry etching and a backing conductive film such as titanium nitrate, called a barrier metal, is formed on a whole substrate surface, including the inside of the contact hole and the insulation film surface. Next, in the case of a contaminating substance on the surface of the barrier metal (for example, titanium barrier metal), cleaning is carried out using plasmas in order to eliminate titanium oxides. Further, a substrate is carried into a CVD chamber without being exposed to atmosphere, and an aluminum film is deposited using DMAH and hydrogen.
Here, in plasma cleaning before depositing aluminum, there are known a method for sputtering a barrier metal surface using inert gas plasmas such as argon, a method for etching a barrier metal surface using plasmas of halogen gas such as chlorine (refer to Japanese Patent Application Laid-Open No. 7-226387), and a method for reducing and eliminating a natural oxide film on a barrier metal surface using hydrogen plasmas (refer to Japanese Patent Application Laid-Open No. 8-298288).
In a conventionally employed positive ion treatment, a positive electric charge is accumulated on a surface of an object during treatment, and the surface potential of the object is electrified with a high positive potential. Even if neutral particles are used, secondary electron emission due to energy shock of neutral particles incident to the object takes place in similar fashion, the surface of the object is positively charged. Even during alternate irradiation of positive and negative ions, although the extent of the electric charge is less than that of only a positive ion treatment, secondary electron emission due to positive ion incidence is not eliminated. Thus, the surface is charged with a high positive potential.
In addition, in cleaning of the conductor surface, oxides cannot be fully eliminated by negative oxygen ions considering metal properties such as continuously deposited aluminum or backing conductor properties. In negative halogen ions, a new design is required for preventing conductor corrosion due to the residual halogen. Even if hydrogen is used, since positive hydrogen ions are primarily used for a conventional plasma treatment, the aforementioned electrification problem will occur.
In particular, when a surface has a groove, specifically, when the surface has irregularities caused by etching patterns or the like, a groove shape failure or a cleaning failure in the groove will often occur.
Thus, charge damage due to charging will occur in the conventional method.
It is an object of the present invention to provide a treating apparatus and method in which damage due to charging is suppressed, and a surface can be surface-treated in a proper state.
It is another object of the present invention to provide a method for manufacturing a semiconductor device in which damage due to electrification is suppressed, and a proper electronic contact state can be obtained when surface treatment of a surface consisting of electric conductors is treated before the conductor is deposited on the inside of the groove.
According to an aspect of the present invention, there is provided a treating apparatus having:
a container;
a support means for supporting an object to be treated in the container,
a gas introducing means for introducing hydrogen gas in the container, and
a plasma generating means for generating a plasma of the hydrogen gas,
which comprises a drawing means for preferentially drawing a negative hydrogen ion from the plasma to the object to be treated, wherein a hydrogen ion group in a state in which a negative hydrogen ion quantity is more than a positive hydrogen ion quantity is supplied to the object to be treated for treatment.
According to another aspect of the present invention, there is provided a method for treating an object to be treated by using the above-mentioned treating apparatus.
According to another aspect of the present invention, there is provided a treatment method wherein a negative ion generated by the treating apparatus 1 is imparted to an object to be treated, thereby performing surface treatment of the object to be treated.
According to another aspect of the present invention, there is provided a treating apparatus having:
a container;
a support means for supporting an object to be treated in the container;
a gas introducing means for introducing hydrogen gas in the container; and
a plasma generating means for generating a plasma of the hydrogen gas, which comprises a metal member for generating a negative hydrogen ion provided so as to come into contact with hydrogen radical and/or positive hydrogen ion generated by the plasma generating means, wherein a hydrogen ion group in a state in which a negative hydrogen ion quantity is more than a positive hydrogen ion quantity is supplied to the object to be treated for treatment.
According to another aspect of the present invention, there is provided a method for treating an object to be treated by using the treating apparatus.
According to another aspect of the present invention, there is provided a treating apparatus having:
a container;
a support means for supporting an object to be treated in the container; and
a gas introducing means for introducing hydrogen gas in the container,
wherein the treating apparatus has a negative hydrogen ion generating means for generating a negative hydrogen ion from a hydrogen gas introduced from the gas introducing means, wherein a hydrogen ion group in a state in which a negative hydrogen ion quantity is more than a positive hydrogen ion quantity is supplied to the object to be treated for treatment.
According to another aspect of the present invention, there is provided a method for treating an object to be treated by using the treating apparatus.
According to another aspect of the present invention, there is provided a process for fabricating a semiconductor device comprising:
a cleaning process for cleaning an interior face of a groove formed at an insulation film provided on a substrate; and
a process for depositing a wiring conductor in the groove, wherein the cleaning process includes the step of supplying into the groove a hydrogen ion group in a state in which a negative hydrogen ion quantity is more than a positive ion quantity to carry out treatment.
According to another aspect of the present invention, there is provided a method for treating a face to be treated comprising:
an electric conductor, the treatment method comprising the process for exposing the face treated to a hydrogen ion group in a state in which a negative hydrogen ion quantity is more than a positive hydrogen ion quantity.
According to another aspect of the present invention, there is provided a process for fabricating a semiconductor device comprising:
a surface treatment process for surface-treating a face to be treated consisting of an electric conductor and a depositing process for depositing an electric conductor on the face to be treated a surface of which has been treated, wherein the surface treatment process includes the step of exposing the face to be treated to a hydrogen ion group in a state in which a negative hydrogen ion quantity is more than a positive hydrogen ion quantity.
According to another aspect of the present invention, there is provided a treating apparatus comprising:
a container for providing a treatment space and a negative ion generating space communicating therewith;
a radical generating space communicating with the negative ion generation space;
an electron supply means connected in the negative ion generation space;
a support means for installing an object to be treated in the treatment space; and
means for supplying the negative ion into the object to be treated.
According to another aspect of the present invention, there is provided a process for fabricating a semiconductor device comprising the step of: forming an insulation film having a recess portion for forming a wire on an object to be treated, forming a barrier metal on a surface of the insulation film and an inside face of a recess portion and a bottom face of the recess portion, cleaning a surface of the barrier metal, and depositing a wiring metal by a chemical gas phase method, wherein the cleaning step for the barrier metal surface is a cleaning comprised of supplying a negative ion to the object to be treated in a treatment space.
According to another aspect of the present invention, there is provided a treating apparatus comprising:
a hydrogen radical generating portion for generating a hydrogen radical;
a negative hydrogen ion generating portion for generating a negative hydrogen ion from the hydrogen radical; and
a container for housing an object to be treated, wherein the negative hydrogen ion comes into contact with the object to be treated.
According to another aspect of the present invention, there is provided a process for fabricating a semiconductor device, comprising the process of cleaning a side wall and a bottom part of a groove of an object to be treated with the negative hydrogen ion by using the treating apparatus.